Duel Binding does not return back to Client

Question

Hi All,

I have a Service Layer object that calls a WCF Service. The WCF Service needs to return data back to the Service Layer Object.
The projects are all .Net 4.0.
I have attached my wcf service and the service Layer object that is trying to consume the wcf service. When I run the wcf Service, the code in the wcf service gets to the callback operation returning channel.
the consumer service, obviously calls the Rates method in the wcf service, and the waitForResponse.WaitOne(); method is called. from the client side it then drops after some time into the exception handler and says that it did not receive a timely response from the service. Even though the service had long gone into the callback statement.
Can anybody see why the OnRatabaseCallback does not get returned to.